(S1W2) Control of Muscle Activation part 3

Question 1

What would the angle graph look like for flexion at the elbow if you start with 0 degrees of flexion?

Answer 1

Question 2

What would the velocity graph look like for flexion at the elbow? Describe what is happening.

Answer 2

• increases slowly
• builds up speed and increases quickly
• slows down rate at which it is increasing
• decreases slowly
• decreases quickly
• decreases slowly towards the end

Question 3

What would the acceleration graph look like for flexion at the elbow? And what is it telling us?

Answer 3

• the movement speeds up then slows down again

Question 4

How does Newton’s 2nd law apply to single joint movements?

Answer 4

• force = mass x acceleration
• force required is proportional to acceleration
• so if the acceleration is positive then negative, the force required to produce that movement will be positive then negative
• a simple movement like flexing you arm, requires a positive force (exciting your bicep) and then a negative force to slow it down (inhibiting your bicep)

Question 5

What would the force graph look like for flexion at the elbow?

Answer 5

Question 6

How are the triceps involved in arm flexion?

Answer 6

• Movements that speed themselves up, stimulate other muscles to slow them down again
• So during arm flexion at elbow, biceps contract and speed up, stimulating the triceps to slow it down